Dockerfile.multistage

# Set FROM image as starting point
FROM golang:1.12-alpine as app

# Set some maintainer info
MAINTAINER Your Name <yourname@yourcompany.com>

# Install prerequisites into the image
RUN apk add -U build-base git

# Add files
COPY app /go/src/app

# Set the working directory
WORKDIR /go/src/app

# Set environment
ENV GO111MODULE=on

# Build the application
RUN go build -mod=vendor -a -v -tags 'netgo' -ldflags '-w -extldflags -static' -o docker-demo .

# Now create a base image and just include the compiled code
# Set FROM image as starting point 
FROM alpine:latest

# Install prerequisites into the image
RUN apk add -U --no-cache curl

# Add files
COPY app/static /static
COPY --from=app /go/src/app/docker-demo /bin/docker-demo
COPY app/templates /templates

# Set environment
ENV COW_COLOR red

# Expose the port for the application
EXPOSE 8080

# Set the entrypoint for the application
ENTRYPOINT ["/bin/docker-demo"]